Some hybrid contact lenses that include a soft material and a hard material have been proposed as lenses that give excellent wearing feel, and has superior oxygen permeability (see Patent Document 1, Patent Document 2 and Patent Document 3). However, according to these lenses, due to a plurality of materials constituting the lens having greatly varying Young's modulus, the difference that results from shape deformation under the same stress condition is significant. Thus, uncomfortable feeling occurs upon blinking, thereby deteriorating the wearing feel.
In addition, since a hard lens containing a silicone component and having a low water absorption rate is significantly inferior in wettability, the wearing feel is extremely deteriorated due to dry feel. Particularly, in the case of conventional hybrid contact lenses, a hard segment having low wettability with water is situated at the farthermost position from the periphery where the lacrimal fluid is supplied although the lens has the same size as those of soft contact lenses. Therefore, sufficient lacrimal film is not provided, and thus the wearing feel is extremely deteriorated by way of drying. In the case in which a hard portion is included in a soft portion as disclosed in Patent Document 4, the wearing feel is similarly deteriorated due to the difference between the original hardness of the hard portion and the hardness at the peripheral portion. It is necessary to subject these hybrid contact lenses to a sterilization treatment; however, when a hard material is used at the central portion, a sterilization treatment carried out by high-pressure steam causes plastic deformation at the hard portion, leading to impairment of the functions of the lens. Although these lenses can be subjected to sterilization with radioactive rays, this process is not practical due to problems in terms of costs and the like. Furthermore, the method disclosed in Patent Document 5 cannot sufficiently secure the amount of oxygen to be supplied to the cornea, due to the absence of a silicone component that is responsible for high oxygen permeability.
In addition, a silicone-containing hydrous soft lens has been also proposed as a hydrous lens including silicone that gives comfortable wearing feel and is superior in oxygen permeability, and which enables continuous wearing, whereas being more superior in retention of the lacrimal fluid than conventional silicone-containing hard lenses and being constituted with a soft identical polymer (Patent Document 6). However, when a hydrous soft contact lens that is superior in optical properties and that enables continuous wearing is produced using this procedure, the Young's modulus of the entirety of the lens increases; therefore the Young's modulus at the peripheral portion which primarily serves in improving the wearing feel is increased, thereby rather leading to deterioration of wearing feel.